Why spend money on expensive energy bars when you can make this easy low carb protein bar recipe with only 5 simple ingredients? These peanut butter protein bars are chewy and fudgy yet they stay firm at room temperature. The recipe is sugar free, low carb, gluten free and Keto.
Shop-bought low carb protein bars
I get it. Shop-bought low carb protein bars are suuper convenient. But they often come with a hefty price tag. Plus, many contain additives to extend shelf life, questionable sweeteners and inflammatory vegetable oils. And while they do solve an immediate problem (=hunger), I’ve never sampled one that actually tastes GREAT.
Easy Keto protein bar recipe
With a teeny-tiny bit of planning ahead, you can make absolutely DELICIOUS FUDGY, CHEWY peanut butter protein bars at home. They’ll boost your energy after a workout and they’re a fat-fuelled, protein-rich snack if you simply need a pick-me-up in between meals.
The main ingredient of this healthy Keto protein bar recipe is peanut butter. Peanut butter already has a high protein content, which I’m boosting with additional protein powder. I never add protein powder to my smoothies (I prefer straight-low carb granola, up veggie smoothies such as this detox Keto green smoothie). But I do like to add a scoop to my granolas because it helps to add extra crunch – check out this the crispy clusters are to die for.)
I experimented quite a bit with this recipe, because originally I wanted to create a no-bake protein bar. The problem with this was that no mix was sufficiently firm at room temperature whilst still fudgy and chewy. I did not want to coat the whole bar in chocolate only to get around that issue.
The solution? 25 minutes in the oven. Yes, a lil’ bit of baking produces absolutely awesomely healthy protein bars that you can carry around all day in your handbag until hunger strikes!
How to make low carb peanut butter protein bars – step by step:
1.) Put the ingredients for the base and the top layer in separate bowls. I decided to use a brown sugar alternative to sweeten, but any granulated erythritol will work.
Your peanut butter should be EASY TO SCOOP. Give it a good stir if necessary – especially in larger pots it tends to settle on the bottom.
2.) Mix your ingredients with a fork and knead with your hands until you have a smooth dough.
3.) Grab yourself an oven-safe container. The mixture will fill a space of 5 x 6 inches. Your dish is larger than that? No problem. Simply fold a bit of aluminium paper and use it as a separator. That way, you can use only part of your casserole dish. The mixture does not spread.
Line the space with parchment paper and fill in first the peanut layer, then the chocolate peanut layer. Or do it the other way around 🙂
4.) After 25 minutes of oven time the bars are ready. This is what you should look out for: The top does not glisten any more. It has set and the edges are beginning to brown.
Wait until your low carb protein bars have cooled down before you cut them. They will be fragile and soft while hot, but firm up as they cool down.
Healthy peanut butter protein bar ingredients
There are plenty of peanut butter protein bars out there that use oats to thicken. I chose coconut flour because not only is it low carb and magnificently healthy, but it also absorbs plenty of liquid. Together with the protein powder, it is the ideal binder.
You can use crunchy or smooth peanut butter in this recipe, whichever you prefer. The bars with crunchy peanut butter can crumble a little when you cut them. If you are after razor-sharp edges, I recommend you use smooth peanut butter.
Always check the label when buying peanut butter to make sure it does not contain added sugar! I like to use the Meridian brand here in the UK – it contains 100% peanuts and nothing else.
You can add 1 tsp of cinnamon for a taste variation or a pinch of salt. If you’re feeling a bit naughty, you could also add a handful of sugar free chocolate chips!
How long do homemade sugar free protein bars last in the fridge?
Your peanut butter bars will keep on the kitchen counter for a couple of days and a good 7 days in the fridge. You can also freeze them. What I love about them is that you can transport them easily. They are a perfect on-the-go snack.
Love peanut butter? Check out these recipes:
- Keto Chocolate Peanut Butter Fudge (Sugar Free Fudge)
- Low Carb Peanut Butter Cookies Recipe (Flourless)
- Grain Free Peanut Butter Granola (Sugar Free)
Tried these peanut butter protein bars? Give them a star rating below!
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Peanut Butter Protein Bars
It's super simple to make absolutely DELICIOUS FUDGY, CHEWY peanut butter protein bars! They'll boost your energy after a workout and they're a fat-fuelled, protein-rich snack if you simply need a pick-me-up on the go.
Ingredients
Base Layer
- 1/2 cup / 130g peanut butter unsweetened
- 1 1/2 tbsp coconut flour
- 1 tbsp protein powder
- 1 1/2 tbsp granulated erythritol
Top Layer
- 1/2 cup / 130g peanut butter
- 1 tbsp cocoa powder unsweetened
- 1 1/2 tbsp powdered erythritol
- 1 tbsp protein powder
- 1 1/2 tbsp coconut flour
Instructions
Preheat the oven to 175 Celsius / 350 Fahrenheit.
Put the ingredients for the base and the top layer in separate bowls and mix with a fork, then knead with your hands to combine.
Line a ovenproof dish with parchment paper. Spread the base layer, then add the top layer to fit a space of ca 5 x 6 inches.
Bake for up to 25 minutes. The bars are ready when the top has set and is beginning to brown around the edges. Remove and let cool to room temperature before cutting.
Recipe Notes
You can use a larger ovenproof dish and only use part of its space. Simply build a divider made with aluminium foil. The mixture does not spread.
You can use crunchy or smooth peanut butter. The crunchy peanut butter bars are a little harder to cut. If you want perfect edges and no crumbles, choose smooth peanut butter.
Patience! The bars will be very soft and fragile while hot, but they firm up as they cool down.
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Betsy says
Can I use powdered peanut butter in this recipe?
Katrin says
I think that powdered peanut butter is fat reduced so you would not achieve the same taste.
Rico says
Looks like basically no carbs (figuring in the sugar alcohol). I like to try and preserve as muscle as I can while on Keto. For taste, would I have to alter the other ingredient for taste it I doubled the protein? If so, what do you suggest?
Katrin says
That’s a good question. You’d add quite a bit more powder, which may make the bars brittle and dry-tasting. I’d add just a little more if you want (amount will depend on how liquid your peanut butter is).
CK says
i’ve made these and they are tasty but very very flat – they do not look like the picture at all! And there wasn’t really enough for 8 large slices as appear in your images. Did I do something wrong?!
Katrin says
Hi Chrissy, if you use the amounts stated in the recipe you should end up with the same amount of bars I did. It’s a lot of peanut butter we’re using! However, if you’re using peanut butter that’s quite liquid it’s possible that it spreads out more. Is this what you’re referring to?
Rebecca :) says
Hi, I’ve just made these but the mixture never ‘glistened’ to start with, so quite hard to tell when they had been baked enough! They’re also quite dry. I substituted agave syrup for the sweetener (just did like for like, so 1.5 tbsp agave syrup instead of the brown sugar substitute) so if anything I’d have thought it should have been wetter pre-bake and gooier post-bake? I used Whole Earth organic crunch peanut butter, and the protein powder was a flavoured one from MyProtein. Would be very grateful for any tips on where you think I went wrong with consistency? Thank you 🙂 They taste great, just dry!
Katrin says
Hi Rebecca, so sorry you had problems with the recipe! I think it’s probably down to the consistency of your peanut butter. I always have a litre pot of Meridian peanut butter. The oil tends to collect on top, so if you don’t stir it up properly, you’ll end up with really hard and crusty peanut butter at the bottom. If your peanut butter is hard to start with, you need to adapt the recipe and use less dry ingredients. I hope this helps and you will give it another go one day 🙂
Rebecca says
HI Katrin, thanks v much for your reply. I bought the Meridian smooth peanut butter today and it’s SO much wetter/more oily than the Whole Earth pb so Round 2 should be the right consistency – thanks for the advice. 🙂
Katrin says
you’re welcome Rebecca!!
Munchie says
Hi, I would like to try making the peanut butter bars but you use erythritol which doesn’t agree with me (IBS). Can you please suggest an alternative sweetener? Thank you!
Katrin says
You can replace it with any sweetener that works for your condition.
Fiona says
Hi,I want to try these out but I’m not sure which protein powder to use. I’m guessing unflavoured would mean I can use it in different recipes but does say chocolate work better here?
Katrin says
Hi Fiona, I think unflavoured protein powder is more versatile. You can add it to smoothies and also to granola for an extra protein boost. If you like the bars extra chocolatey, just add more cocoa powder 🙂
Fiona says
Thanks Katrin, so glad I found your site. I really struggle to find gluten free recipes that aren’t hugely com pled but still taste of sadness. I can’t wait to try these out ☺
Maeve says
Can you use coconut sugar instead of granulated erythritol? 🙂
Katrin says
Yes, absolutely!
Megan says
What can i substitute the coconut flour with, I’m allergic to any coconut products.
Thank you
Megan
Katrin says
Hi Megan, I’d replace it with 3 tbsp almond flour.
Dawn says
I am trying to work out how many pieces this makes to calculate the calories. Can you advise?
Katrin says
I always calculate the nutrition per portion. I cut 8 pieces, so the calories are stated per protein bar/= 1 portion. They are filling, so you could also cut into 16 squares and halve your calories.
Desiree Currie says
My daughters kindergarten is ‘peanut free’ – do you think this recipe would hold together as well with almond or cashew butter for example? If not I’ll still make it – as an afternoon/home snack
Katrin says
Yes, absolutely. Sometimes my almond butter is more liquid than peanut butter. If you cannot knead the “dough” without getting sticky hands, just add an extra 1/2 tbsp of coconut flour. Alternatively, you can also leave the mix in the oven for longer.
Colleen Schoneveld says
to Desiree. If your child’s school is “Peanut free” they actually mean “Tree nut free” as well.
The best substitute for peanut butter is Sunflower butter. Though it is expensive.
Ruth Gallagher says
what can i substitute for the protein powder plz?
Katrin says
Hi Ruth, I would try with either 1 tbsp almond flour OR an additional 1/2 tbsp coconut flour – but I haven’t tried this myself. I think this recipe can handle all kinds of substitutions. All you want is to make sure your mix does not get too dry. The bars will still taste good, but they will become brittle and crumbly.
Ruth Gallagher says
thanks so much, going to make these over the weekend
Scally Wag says
Hi…. these look great! Can you use an extra tblsp if coconut flour instead of protein? Im not keen! Or is there anotjer alternative? Thanks!
Katrin says
I would try 1 tbsp almond flour or 1/2 tbsp coconut flour instead of the protein powder. Coconut flour absorbs so much liquid, probably more than protein powder. You don’t want your mix to get too dry. But that will also depend on how liquid your peanut butter is. It’ll be a bit of trying out.
Elyse says
Do you have to use whey protein or can you use a plant-based one? I have a plant-based protein powder that I would like to use instead of going out to but yet another powder.
Katrin says
Of course, you can use any protein powder in this recipe.
Elyse says
Perfect! Thx!